[Chiara, Jenne]

It's pretty windy and earthquake-y, so we took some time to measure the HAM3 to MC2 transfer function (so we don't have to do this in the morning during maintenance).

We drove at the error point of the isolation loop in X, since that is where our MC2 length offloading will inject.  We monitored MC2 both at the M1_LOCK_L_OUT and at the the M3_ISCINF_IN1 (although I should have probably taken the output of the ISCINF filter). 

We did bandpassed white noise injections, in 3 different bands, to see some coherence.  In the attached screenshot, the left plot is with the M1 stage as the monitor point, while the right is M3.  The red is coherent up to about 0.1 Hz, the green traces are coherent between about 0.2 Hz - 2 Hz, and the blue traces are coherent from about 0.5 Hz to 8 Hz.  We'll need to extract the data and stitch these together to make one single nice measurement, but then we can use this to help design our suspension length offloading.  The measurement in the left plots looks very similar to the LLO version of the measurement, reported in LLO alog 49151 (blue trace in 1st fig).